With rapid development of packet services and intelligent terminals, spectrum requirements of a high-speed and large-data-volume service are increasing, and higher spectrum efficiency needs to be achieved. In a Long Term Evolution Advanced (LTE-A) system, an LTE-A cellular communications technology is applied to an unlicensed spectrum by means of licensed-assisted access (LAA), to improve utilization of an unlicensed spectrum resource and increase available spectrum bandwidth of an LTE user. The unlicensed spectrum includes a frequency band for devices used in industry, science, and medical applications and the like. LAA means a scenario of carrier aggregation (CA) based on a licensed spectrum and an unlicensed spectrum. A carrier on a licensed spectrum is used for a primary serving cell (PCell), and a carrier on an unlicensed spectrum is used for a secondary cell (SCell). The PCell is a cell in which user equipment (UE) is located when the user equipment initially accesses a system in a random access process or a cell in which user equipment is located when the user equipment accesses a target eNodeB in a handover process. The PCell can provide security and non-access stratum (NAS) signaling transmission. The SCell mainly provides an additional radio resource for data transmission.
In the prior art, an LTE-A dual connectivity (DC) technology is introduced, so that different eNodeBs provide carriers required when CA is performed to UE, and the UE can perform communication with two eNodeBs simultaneously or non-simultaneously. This can increase a peak rate and a throughput at a cell edge to some extent.
However, in the prior art, it is not supported that a primary secondary cell (PSCell) served by a secondary eNodeB (SeNB) uses a carrier on an unlicensed spectrum in the LTE-A DC scenario.